220 volt converter

Hello to all. I was going through my shop notes (Vol 20, issue 118, pg 49), and came across an item that converts 2-110volt outlets to 220volts(220 converter) The 220 converter plugs into two outlets on different circuits and it steps up your 110 volts to 220 volts, so you could use 220 volt equipment. I will eventually be running 220 in my shop, but for now with two kids in college, I can’t swing it. This option sounds like it would work in the mean time, and it opens my search for a more powerful table saw:) Has anyone used this, and if so did it work?

Thanks to all in advance. This is a great site with very knowledgeable woodworkers.

-- Joe from Western Ma.... Peace to all

12 replies so far

I would strongly urge you to NOT use this technique. If you do in fact have two 110 volt outlets available that are on “opposing” circuits, using this would “work” but would deprive you of the proper circuit breaker protection. 220 volt circuits are protected by a double circuit breaker, one for each hot side of the line. The breakers are mechanically linked, so if there is an over-current problem on the circuit both breakers trip open. The contraption / arrangement you describe would allow only one breaker to trip. This would kill power on that side of the line but would leave the other side hot. If you didn’t know what was going on you could well come in contact with the side that was still how. This is potentially a deadly device in my opinion and I recommend you do not use it.

Joe – It will work. In fact it is essentially the same as running a separate 220V circuit except as Herb said caution is needed. Both legs would be protected by the individual CBs that the 120V outlets use but if one CB blows the other might not and therefore the circuit still hot with the un-tripped 120V circuit. Also each 120V leg would potentially be providing current to other loads on its individual circuit.

First of all, you would need to make sure that there are 240 volts differential between the two “hots.” They would need to be on seperate circuits, and the separate circuits would need to be on different “legs” in your circuit box. You would probably not have over 12 amps through the neutral, so you are probably ok there.

I can see how THEORITICALLY it would work, but it would scare the hell out of me (and I did 99% of the wiring when I added my sub panel in my garage). I would also be scared about it invalidating my insurance.

Let’s see what the EE’s and electricians think here.

Scott

Edit: other guys got in while I was thinking and typing :)

I am with the other guys that say add the 220 if you can. I went through the hassle of pulling a homeowner’s electrical permit (had to pass a county test on the first 4 chapters of the NEC), and did most of the work myself. I had an electrican friend come over to make sure I was making the aluminum connections on each end for the sub panel correctly. Total cost for me for the sub and 4 circuits in the garage was about $800 (would have been 650 but I messed up a 70 foot length of SER).

I just had to run a 220volt line outside to a hot tub I recently purchased used for $500. I tried calling an electrician. The cost of that was ranging $850-$1500. I was not about to spend more on hooking the thing up than what I paid for it. I decided to run the line and do the install myself. While I was at it I ran a new 110volt circuit in my basement. I have never done home electrical before. What a piece of cake! I say go get a book and teach yourself how to wire your shop yourself. It was a very satisfying experience and much much easier than I thought it would be.

Good Luck,Jeremy

-- I tell you, we are here on Earth to fart around, and don't let anybody tell you different. -Kurt Vonnegut

i believe the item the OP is referencing has incorpoorated circuitry that addresss all the noted concerns. but it isn’t an inexpensive solution. the 20A version retails for $200+. there aren’t a whole lot of electricians who charge more than that for a 20A 220v home run to an exposed panel, provided it’s within a few feet of the supply panel. heck, the breaker is well under $20 and the outlet box, mud ring, outlet and cover plate add another $15 in parts (total of $35). i pull all my electrical myself, so we know it’s not that hard.

Thank you all for your sound advice, that I will heed. The problem I have, is my box is only a 60 amp. ( 4 – 15 amp breakers) and I am at my max. As stated before, I do want to put in a 100 amp service, and at that time I will have 220 V put in to the shop. Guess I can wait for my cabinet saw:)

220 volts is made with TWO 110 volt circuits that are 180 DEGREES OUT OF PHASE WITH EACH OTHER!!!

For this reason I doubt that device you mention would work unless the two 110 volt lines you selected just happened to be out of phase or the device somehow acted as a phase inverter and inverted one of the 110 volt lines.

To understand 220 volt current in the USA, do some studying about how it is accomplished. Its is actually very simple once you understand it.

Planeman

-- Always remember: It is a mathematical certainty that half the people in this country are below average in intelligence!

Planeman sez: ”220 volts is made with TWO 110 volt circuits that are 180 DEGREES OUT OF PHASE WITH EACH OTHER!!!

For this reason I doubt that device you mention would work unless the two 110 volt lines you selected just happened to be out of phase or the device somehow acted as a phase inverter and inverted one of the 110 volt lines.”

Exactly what the OP stated kinda.. Two different 110V circuits that would have to be on different legs in your breaker box. Could easily be wired up.. find two 110V outlets that are on opposite sides of the breaker box feeds and you magically have 220V. To get around the separate breaker problem, you could run the individual 110V wires into a box containing a 220V breaker. Not pretty, not to code, not very smart, but doable if you really had to.

To the OP, do you have a clothes dryer in the house? A 50 foot or so extension could be wired up pretty cheaply for a temporary solution until something more permanent could be installed.

Cheers,Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

planeman40 sound advice. I have a healthy respect for electricity, but I am not so paralyzed that I can't do some basic wiring, will definitely do some reading. MrUnix, I am not in such a rush where I will do something foolish just to get the 220V. I do foolish things from time to time, but not with electricity.

This will not work if you have GFCI protected circuits. GFCI works by comparing the currents in the “hot” and “neutral” and tripping if there is any difference between them. This little trick allows current to flow from one “hot” to the other “hot” with no neutral return current.

Recent NEC requires GFCI protection in attached or detached garages, so if you have a garage shop and your house is fairly recent, you have GFCI.

I am currently (pun intended) rewiring my detached garage shop and have spent way too much time with the NEC lately.

EEngineer, thanks for the tip. I did notice in the write up I read that this unit would not work on GFCI circuits. I’m going to hold off getting this converter. I’m glad I checked with you all first. I appreciate the sound advice.